Our invention relates to an apparatus commonly known as a disk drive, for data transfer with a flexible magnetic disk or like data storage medium. More particularly, our invention pertains to a disk drive with facilities for its mechanical connection to a computer, word processor, or like data processing instrument without any such strain as would adversely affect the performance of the disk drive.
Flexible magnetic disk drives are usually not self contained but are subservient to such data processing equipment as computers and word processors. Many computers and word processors on the market today have built in disk drives because of the widespread acceptance of flexible magnetic disks as compact and inexpensive data storage media. The usual practice in coupling a disk drive to a data processing instruments is to screw the frame or base structure of the disk drive to the housing of the data processing instrument. Usually fabricated by aluminum die casting, the base structure includes a broad platform on which there are mounted such standard components of the disk drive as the disk drive mechanism for imparting rotation to the flexible magnetic disk, and the head transport mechanism for transporting a magnetic transducer head or heads radially of the magnetic disk. The base structure has tapped holes predefined therein for receiving screws or the like that also pass clearance holes preformed in the housing.
A problem has existed, however, in thus fastening the base structure of the disk drive to the housing of the data processing instrument. The screw holes in the disk drive base structure are not necessarily in precise axial alignment with the clearance holes in the data processing instrument housing. Consequently, with the forced insertion of screws in such misaligned holes, the disk drive base structure of aluminum die casting is very likely to be strained, the data processing instrument housing being generally greater in rigidity. The straining of the base structure can seriously affect the performance of the working components of the disk drive mounted thereon. For example, if the screw holes in the disk drive base structure and the clearance holes in the data processing instrument housing are displaced from 0.2 to 0.3 millimeter out of axial alignment, the magnetic transducer head or heads of the disk drive may be displaced as much as five microns, or even more, in a radial direction of the magnetic disk.